Nowadays, personal digital assistants (PDA), mobile phones, notebook computers, tablet PCs and other portable electronic products are commonly used in modern life. Since these electronic products need to be thinner and lighter, the traditional input devices, such as keyboards or mice have to be replaced with other input devices. In addition, the needs for tablet PCs has greatly increased, hence the touch panel technology has became one of the key components in electronic products. Besides, the organic light emitting display (OLED) has some advantages such as thinning, low weight, low power consumption, high brightness, high response speed, so it also commonly used in mobile electronic devices.
In the technology of combining the touch panel and the OLED, usually, the touch panel and the OLED are formed separately in individual processes, and then combined with each other. The OLED provides the function for displaying, and the touch panel provides the function for interacting with the user. The position data detected by the touch panel and displaying data of the OLED are connected to each other and then calculated through the outside traces and the operation systems. Therefore the touch panel becomes heavy and thick, and is hardly able to achieve the lightened and thinned requirements. Besides, PET (polyethylene terephthalate) is usually used as the substrate of a large-size touch panel, but some common materials for forming the electrodes such as indium tin oxide (ITO) are fragile and not suitable for forming on the flexible PET film. In addition, some issues such as PET substrate can't endure high temperatures, or the conductivity of the ITO electrode can't satisfy the rapid scanning requirements of the large-size touch panel still need to be resolved.